1. Field of the Invention
This invention relates generally to cassette tape recording and/or reproducing apparatus, and more particularly is directed to a cassette loading device for a tape recording and/or reproducing apparatus of the type in which the tape is withdrawn from a cassette housing for recording and reproducing information signals on the tape.
2. Description of the Prior Art
The conventional tape cassette for the recording and/or reproducing of audio signals is provided with a plurality of openings at one side of the cassette housing through which a magnetic recording and/or reproducing head, a pinch roller, capstan and the like may be inserted into the cassette housing to record and/or reproduce signals on the tape while the latter is driven or transported in a predetermined direction. However, in such a tape cassette, the number and size of the openings that may be formed in the cassette housing are limited and this, in turn, limits the number and size of the magnetic heads that may be employed for recording and reproducing operations. Accordingly, in existing tape recording and/or reproducing apparatus intended for use with tape cassettes of the described type, that is, in which the tape remains wholly within the cassette housing during recording and reproducing operations, the magnetic head used for reproducing signals recorded on the tape is also used, in association with an erasing head, for recording new signals on the tape. It is known that the use of the same magnetic head for both recording and reproducing operations limits the quality of the audio or other information signals that may be recorded and reproduced thereby. Further, when the magnetic recording and/or reproducing head is inserted into the cassette housing for engagement with the tape therein, as aforesaid, it is difficult to ensure the precise positioning of the tape relative to such head, and variations of the position or path of the tape relative to the recording and/or reproducing head also deleteriously affect the quality of the recorded and reproduced signals.
Therefore, when it is desired to obtain high quality recording and reproducing of audio or other information signals, it has been the usual practice to employ apparatus of the so-called open-reel type having separate or individual heads for respectively recording and reproducing signals on the tape which is precisely guided relative to such heads in the run of the tape between the supply and take-up reels. However, apparatus of the open-reel type has the well-known disadvantages of requiring the manual threading of the leader or end portion of the tape from the supply reel past the guide pins and heads, and between each capstan and associated pinch roller to the take-up reel when installing a tape on the apparatus, and of requiring rewinding of the entire tape onto the supply reel when one tape is to be exchanged for another.
In order to avoid the above described disadvantages of recording and reproducing apparatus of the open-reel type and the limitations on the quality of recording and reproducing previously attainable with cassette type recording and reproducing apparatus, it has been proposed, for example, as disclosed in United Kingdom Patent Specification No. 1,121,125, published July 24, 1968, to provide a cassette from which the tape is withdrawn when signals are to be recorded or reproduced thereon by means of respective magnetic heads which are disposed outside of the cassette housing. However, in cassettes intended for use with such apparatus, a run of the tape is exposed at the exterior of the cassette housing even when the cassette is not in use, so that the exposed tape is susceptible to being damaged or even severed and will collect dust thereon.
The exposure of the tape when the cassette is not in use may be avoided by the cassette arrangement disclosed in U.S. Pat. No. 3,900,171, issued Aug. 19, 1975, and having a common assignee herewith. In such cassette, the housing has spaced parallel walls with an opening therebetween extending along one side of the housing, and a lid is provided which is normally spring-biased and locked in a closed position to cover the tape extending along such open side of the cassette housing when the cassette is not in use so as to protect the tape from damage thereto. However, in this previously proposed tape cassette, the lid is pivotally mounted for movement in respect to the housing about an axis which extends along the open side of the housing and is parallel to the planes of the spaced walls thereof. Therefore, in moving about such axis from its closed position to an opened position, the lid has to be moved across the plane of one of the spaced parallel walls of the cassette housing, for example, the wall which is at the top of the cassette housing in the normal operating position of the latter. In other words, the lid has to be moved in the upward direction from its closed position to its opened position when the cassette is in its normal operating position. Thus, if a recording and/or reproducing apparatus for use with a tape cassette of the described type is provided with a suitable mechanism for effecting the upward opening movement of the lid prior to the withdrawing of the tape from the cassette housing for a recording or reproducing operation, the cassette can be used only in the one orientation in which the lids open upwardly. In other words, the cassette cannot be inverted for a recording or reproducing operation, as the lid would then open downwardly and could not be actuated by the existing lid opening mechanism. Thus, the described tape cassette cannot be used for recording and/or reproducing operations of the type in which, for example, one or more tracks on the tape are used for recording or reproducing information signals with the cassette in one orientation, and the cassette is inverted for permitting recording or reproducing of information signals in one or more other tracks on the tape.
In order to avoid the above described disadvantages of the tape cassette having its lid swingable from a closed position to an opened position about an axis extending along the open side of the cassette housing, it has been proposed, for example, as disclosed in U.S. Patent Application Ser. No. 636,829, filed Dec. 2, 1975, now U.S. Pat. No. 4,022,395 and having a common assignee herewith, to provide a tape cassette with a housing having spaced parallel walls with an opening therebetween at one side of the housing along which a run of the tape is normally guided, and lide mounted for pivoting relative to the housing about respective axes which are perpendicular to the spaced parallel walls adjacent the opposite ends of the open side of the housing, so that the lids are movable relative to the housing in directions parallel to the planes of the spaced walls thereof between closed positions where the lids extend along the open side for covering respective parts of the tape run and opened positions where the lids are displaced from the opening to permit the withdrawal of the tape therethrough. By reason of such movable mounting of the lids, the same lid opening mechanism can be employed for opening the lids when the cassette is operatively positioned in either one of two relatively inverted orientations. However, in the existing tape recording and/or reproducing apparatus for use with a tape cassette of the last described type, either a separate lid opening mechanism is provided for opening the lids after the cassette has been brought to its operative position by a movable cassette holder, or a lid opening mechanism is combined with the tape withdrawing means by which the tape is withdrawn from the cassette housing and moved into engagement with the recording and/or reproducing heads and the tape drive capstan which are spaced from the operatively positioned cassette. If a separate lid opening mechanism is provided, as aforesaid, the structure and operation of the recording and/or reproducing apparatus are made undesirably complex, and a substantially large clearance has to be provided between the heads and capstan and the operatively positioned cassette to permit the swinging of the lids to the opened positions. On the other hand, if the lid opening mechanism is combined with the tape withdrawing means, then the lids remain in their closed positions during fast-forward and rewind operations of the recording and/or reproducing apparatus so that the lids may come into contact with and mar the tape while the latter is being moved at high speed during such operations.